A background technique in the present technical field is, for example, JP-A-2006-23445 (PTL 1). This literature includes, as a problem, the description that “at the time of recording a hologram by an angle-multiplexing recording method, even if the angle of incidence of a reference beam is changed, the area exposed to this reference beam on a holographic recording material is to be made constant at any time”. As a solution, the literature includes the description that “in changing the angle of a scan mirror 12 in order to change the angle of incidence of a reference beam 200 on a holographic recording material 15, the slit 11 is linked to this and changed in the angle thereof, thus causing the beam diameter of the reference beam 200 to be changed by the slit 11 in such a way that the range of exposure on the holographic recording material 15 is not changed by the change in the angle of incidence of the reference beam 200 but stays constant. Therefore, at the time of recording a hologram by an angle-multiplexing recording method, even if the angle of incidence of the reference beam 200 is changed, the area exposed to this reference beam 200 on the holographic recording material 15 can be made constant at any time.” Also, JP-A-2006-78942 (PTL 2) includes, as a problem, the description that “at the time of recording a hologram by an angle-multiplexing recording method, even if the angle of incidence of a reference beam is changed, the area exposed to this reference beam on a holographic recording material is to be made constant at any time without causing mechanical wear and without impairing the high scanning speed and the small and lightweight configuration.” As a solution, the literature includes the description that “if a diffraction grating 111 and a holographic recording material 14 are arranged in a relation for imaging with each other via a telecentric optical system made up of lenses 12, 13, even if the angle of incidence of a reference beam 200 is changed by the diffraction grating 111 and the angle of incidence on the holographic recording material 14 is thus changed, the exposure area exposed to the reference beam 200 on the holographic recording material 14 can be made constant since the diffraction grating 111 and the holographic recording material 14 are in a relation for imaging. Moreover, this effect can be realized without impairing the high scanning speed and the small and lightweight configuration and without causing mechanical wear.”